I got my 1994 Trans am scanned and returned with a code 36 for high resolution pulse failure. They scoped both crankshaft sensor signals and found x24 waveform is erratic. I'm told I need a new distributor assembly, I already have an msd opti spark distributor, so for me this is a little f***ing weird to me. Is there any other faults that would cause this? And do I absoulty have to replace the whole distributor assembly?

 

Opti or wiring between the opti and PCM. In rare occurrences, a leaky plug wire routed near the harness will cause issues. Make sure all your connections and wiring are sound. If it is the opti, then the sensor is flaky and replacing the opti is the only choice, since you cannot buy the sensor. MSD does have a program where you can send yours in to be refurbished (less money than buying a new one).

 

The MSD distributor is NOT a particularly good piece, don't delude yourself into blindly believing it can't be the problem.